I. Field of the Invention
The present invention relates to a system for extending the effective operational range of an infrared remote control system of the type used with audio and video equipment.
II. Description of the Prior Art
There are many types of previously known remote controlled electronic devices which utilize an infrared signal between a remote control unit and the controlled device. Such types of previously known controlled devices include, for example, VCRs, television sets, audio amplifiers, and the like.
One disadvantage of these previously known infrared remote control systems is that the operational range of the remote control unit is limited to a line of sight path between the infrared transmitter at the remote control unit and the infrared receiver at the controlled device. In many instances, however, it is highly desirable to operate the controlled device from more than one room.
One previously known device for allowing the controlled device to be operated from more than one room is disclosed in U.S. Pat. No. 4,509,211 which issued on Apr. 7, 1985 to Robbins. In the Robbins patent the range for the infrared remote control system is effectively increased by utilizing a pair of transducer units which are electrically coupled together by a wire transmission line. This previously known system, however, is disadvantageous in several different respects.
First, in this previously known device, it is necessary to physically connect the transducer units together with a transmission line. In many cases, depending upon the location of the controlled device and the desired location of operation of the remote control unit, it is necessary to drill holes through walls, floors and the like in order to obtain the needed electrical connection.
A still further disadvantage of these previously known systems is that, if the control device is to be operated from two or more locations, a hard wire must be connected from each of the remote locations into the room containing the controlled device. Furthermore, a multiplexer circuit is required in order to electrically connect the multiple hard wire connections to the transducer unit adjacent the controlled device.